Optimism

Optimism is a classic and inspirational essay by Helen Keller on the topic of optimism that serves as one of the best self-help books that one could find.

This great work contains this snippet:
Could we choose our environment, and were desire in human undertakings synonymous with endowment, all men would, I suppose, be optimists. Certainly most of us regard happiness as the proper end of all earthly enterprise. The will to be happy animates alike the philosopher, the prince and the chimney-sweep. No matter how dull, or how mean, or how wise a man is, he feels that happiness is his indisputable right.